A mobile self-leveling landing platform for small-scale uavs

ABSTRACT

A mobile self-leveling landing platform vehicle is disclosed that includes a landing surface and one or more wheel assemblies. Each wheel assembly includes a wheel, a control arm coupled with the wheel and the body of the landing platform vehicle, and an actuator coupled with the control arm and the body of the platform vehicle. Methods for self-leveling the landing platform vehicle are also disclosed.

This disclosure relates generally to mobile self-leveling landingplatforms for small-scale unmanned aerial vehicles.

BACKGROUND

The ever-increasing popularity of autonomous Unmanned Aerial Vehicles(UAVs) for both military and civilian applications has created a needfor increased autonomy in the deployment of UAVs in the field. Recentyears have seen a significant increase in the capabilities of small(<150 kg) Vertical Take-Off and Landing (VTOL) UAVs. At the same time,these vehicles have become more accessible and less expensive. Despitethe rapid growth, there have been few solutions offered to address theproblem of launching and recovering UAVs without human intervention. Oneof the difficulties associated with VTOL aircraft is that they cannotland safely on slopped or uneven terrain. This is primarily due to thephysics of rotorcraft UAVs in which the thrust force is alwaysperpendicular to the landing gear; if the vehicle is oriented to matchan uneven landing surface, the vehicle may not be able to maintainflight. Additionally, when the landing surface is uneven, there is ahigher chance of touching the ground with one of the rotors, causingcatastrophic failure of the vehicle. While a fixed-wing aircraft canoperate on a sloped landing strip by taking off traveling down the slopeand land while traveling back up the slope, VTOL aircraft cannot.

SUMMARY

A mobile self-leveling landing platform vehicle is disclosed thatincludes a landing surface and one or more wheel assemblies. Each wheelassembly includes a wheel, a control arm coupled with the wheel and thebody of the landing platform vehicle, and an actuator coupled with thecontrol arm and the body of the platform vehicle. Methods forself-leveling the landing platform vehicle are also disclosed.

These illustrative embodiments are mentioned not to limit or define thedisclosure, but to provide examples to aid understanding thereofAdditional embodiments are discussed in the Detailed Description, andfurther description is provided there. Advantages offered by one or moreof the various embodiments may be further understood by examining thisspecification or by practicing one or more embodiments presented.

BRIEF DESCRIPTION OF THE FIGURES

These and other features, aspects, and advantages of the presentdisclosure are better understood when the following Detailed Descriptionis read with reference to the accompanying drawings.

FIG. 1 illustrates a self-leveling landing platform with a UAV accordingto some embodiments.

FIGS. 2A, 2B, 2C and 2D illustrate examples of the relationship betweenthe linear actuator, the control arm and the wheel according to someembodiments.

FIG. 3 illustrates another embodiment of a landing platform with a UAVaccording to some embodiments.

FIG. 4 illustrates a free body diagram of the control arm and actuatorin the self-leveling system according to some embodiments.

FIG. 5 graphically represents a plot of F_(LIFT) vs. control arm anglefor an example of a self-leveling system.

FIG. 6 illustrates a wheel motor and a wheel mounted to a control armaccording to some embodiments.

FIGS. 7A and 7B illustrate a collapsible landing surface according tosome embodiments.

FIG. 8 is a block diagram of a landing platform according to someembodiments.

FIG. 9 is a flowchart of a method for self-leveling according to someembodiments.

FIG. 10 illustrates a computational system for performing functionalityto facilitate implementation of embodiments described herein.

DETAILED DESCRIPTION

Systems and methods are disclosed among other things for a self-levelinglanding platform for a UAV.

FIG. 1 illustrates a self-leveling landing platform vehicle 100 with aUAV 105 according to some embodiments. The landing platform vehicle 100may include a landing surface 102 and may be coupled with at least fouractuating wheel assemblies. Each actuating wheel assembly may include awheel 125 coupled with a control arm 130. Each control arm 130 may beindependently actuated by a linear actuator 135. An actuating arm 136 ofthe linear actuator 135 may be coupled with the control arm 130 and thebody of the landing platform vehicle 100. In some embodiments, eachwheel may be placed at one of four corners of the landing platformvehicle 100. The linear actuators 135 may be independently actuated toraise and/or lower portions and/or corners of the landing platformvehicle 100 and/or to adjust the level of the landing surface 102.

By raising or lowering the height of each wheel 125 independently and/orin conjunction with one or more of the other wheels 125, the landingsurface 102 can maintain a level surface regardless of the slope of theground upon which it is placed. For example, the landing surface 102 maymaintain a horizontal surface despite the landing platform vehicle 100being on a slope up to 25 degrees regardless of the orientation of thelanding platform vehicle 100.

Each wheel 125 can be mounted on the end or near the end of the controlarm 130. The control arm 130, for example, may pivot about a fulcrum 145when actuated by the linear actuator 135. The linear actuator 135 mayrotate the control arm 130 causing the associated wheel 125 to move upand down relative to the landing platform vehicle 100. FIGS. 2A, 2B, 2Cand 2D illustrate examples of the relationship between the linearactuator 135, the control arm 130, and the wheel 125 according to someembodiments. In FIG. 2A the linear actuator 135 is not actuated and thewheel 125 is extended away from the landing platform vehicle 100 on thecontrol arm 130. In FIG. 2B the linear actuator 135 is partiallyactuated causing the wheel 125 to move downward relative to the landingplatform vehicle 100. In FIG. 2C the linear actuator 135 is actuatedmore than in FIG. 2B causing the wheel 125 to move downward relative tothe landing platform vehicle 100. In FIG. 2D the linear actuator 135 isfully or near-fully actuated causing the wheel 125 to be positioneddownward from the landing platform vehicle 100.

As shown FIGS. 2A, 2B, 2C, and 2D, positive actuation of a linearactuator 135 can cause an associated wheel 125 to move downwardly, whichmay cause a portion of the landing platform vehicle 100 and/or a portionof the landing surface 102 to move upwardly relative to the ground.Similarly negative actuation of the linear actuator 135 can cause anassociated wheel 125 to move upwardly, which may cause a portion of thelanding platform vehicle 100 and/or a portion of the landing surface 102to move downwardly relative to the ground. By coordinating the positiveand/or negative actuation of the linear actuators 135 a portion of thelanding platform vehicle 100 and/or a portion of the landing surface 102may change the angular orientation of the landing surface 102 relativeto the horizon and/or may position the landing surface 102 into a levelorientation in two dimensions.

FIG. 3 illustrates another embodiment of a landing platform vehicle 100with an unmanned aerial vehicle (UAV) 105 according to some embodiments.

In some embodiments, the landing surface of the landing surface 102 mayinclude a plurality of solar cells that may be used to charge batteriesand/or power various electrical components. When the UAV 105 may not beon the landing surface of the landing surface 102, the landing surface102 may be angled and/or positioned, for example, so the solar panelsmay be optimized to collect sun rays such as at an angle that may beclose to ninety degrees relative to the direction of the sun rays. Forexample, the power (e.g., voltage and/or current) produced by the solarcells may be monitored while the landing surface 102 is tilted. Thelanding platform vehicle 100 may find a tilt position of the landingsurface 102 that produces an electrical power that is greater than othertilt positions.

FIG. 4 illustrates an example free body diagram of the control arm 130and linear actuator 135 in the self-leveling system according to someembodiments. In the free body diagram, F_(linear actuator controller) isthe force provided by the linear actuator 135 on the control arm 130,F_(WTE) is the force provided by the wheel motor that can rotate inwardto provide additional force at low transmission angles, and F_(LIFT) isthe resulting lifting force that may be applied at the wheel 125 to liftthe corner of the landing platform vehicle 100. The angle between thelinear actuator 135 and the control arm 130 is represented by θ (theta)which is the transmission angle, and the angle between the control arm130 and the ground is represented by φ (phi). As the linear actuator 135extends, the angle θ decreases and the angle φ increases. Because thesetwo angles may be dependent on one another, one can be written as afunction of the other. The lifting force F_(LIFT) is dependent on theseangles, and changes as the control arm 130 moves through its range ofmotion according, for example, to the following:

$F_{LIFT} = \frac{{0.1\left( {F_{LAC}\sin \; \theta} \right)} + {0.225\left( {F_{WTE}\cos \; \phi} \right)}}{0.225}$θ = −0.558ϕ + 53.049 − 4.41^(∘) ≤ ϕ ≤ 76.48^(∘)∴ 43.3N ≤ F_(LIFT) ≤ 188.9N

These values may change based on the weight and/or dimensions of thelanding platform vehicle 100, each linear actuator 135, the control arm130, etc. This relationship may be further illustrated, for example, inFIG. 5, which graphically represents a plot of F_(LIFT) vs. control arm130 angle (φ) for an example of a landing platform vehicle 100.

In some embodiments, each linear actuator 135 may be individuallycontrolled using a linear actuator controller. The linear actuatorcontroller, for example, may include a standard controller. In someembodiments, each linear actuator 135 may be controlled by a separatelinear actuator controller. In other embodiments, a central controllermay act as the linear actuator controller for multiple linear actuators135. In some embodiments, the linear actuator controller may allow eachlinear actuator 135 to operate like servomotors.

In some embodiments, a control signal, for example, may dictate thedesired position set-point of a linear actuator 135 rather than thespeed at which it moves. For example, a 1.0 kHz Pulse Width Modulation(PWM) signal may be used to control the position of each linear actuator135 through the linear actuator controller, which may use internalpotentiometer position feedback to achieve the desired extension length.The potentiometer position feedback may be built into each linearactuator 135, and may function by changing the electrical resistance(e.g., from 5 to 10 KΩ) between a reference wire and a signal wiredepending on the amount of extension. A low voltage (e.g., 3.3 Volts)may be provided to the reference wire, and as the linear actuator 135extends the resistance decreases and the voltage at the signal wireincreases, according to Ohm's Law. The linear actuator controller mayread the voltage at the position feedback signal wire, and determine howfar the linear actuator 135 needs to extend or retract to reach thedesired set-point set by the PWM signal. The duty cycle of the PWMsignal can range, for example, from 0% to 100%, which may correspond toa position set-point ranging from fully-refracted to fully-extendedrespectively.

In some embodiments, a plurality of linear actuator controllers may becoupled with a processor (e.g., computational system 1000 in FIG. 10 orcontroller 805 in FIG. 8) to control the operation of the various linearactuators 135.

In some embodiments, each linear actuator controller may be afully-functioning stand-alone closed-loop controller, which handles allof the calculations necessary to reach the desired position and maintainthat extension length until the PWM input signal changes. The linearactuator controller, for example, may use a software based controlalgorithm, which allows all of the parameters of the controller to betuned by the user. In some embodiments, this ability to tune each linearactuator controller individually to optimize the performance of itscompanion linear actuator 135 may be used to ensure that the landingsurface 102 can remain within ±one degree of level. In some embodiments,all four linear actuators 135 may be the same model from the samemanufacturer, although they may not all operate exactly the same rightout of the box. This may be primarily due to the fact that thepotentiometer feedback may not be identical in every linear actuator135. For example, two similar or identical linear actuators 135 may beconnected to similar or identical linear actuator controllers and giventhe same 50% PWM signal should both extend to exactly 50 mm. In reality,however, one linear actuator 135 might extend to 51 mm and the other to48 mm. This small discrepancy may have an effect on the performance ofthe self-leveling system and drive system of the landing platformvehicle 100. In some embodiments, tuning the linear actuator controllersindividually eliminates these types of problems.

The landing platform vehicle 100 may include a controller that candetermine the present angle of the landing surface 102 with respect toflat ground (e.g., the horizon) in order to level the landing surface102. In some embodiments, the landing platform vehicle 100 may includean inclinometer that measures the angles in the X- and Y-axes withrespect to the direction of the Earth's gravitational pull. The datafrom the inclinometer readings can range from 0 to 180 degrees, with 90degrees being considered perfectly level. In some embodiments, the angleof the X-axis corresponds to the incline between the front and back ofthe landing platform vehicle 100, and the Y-axis corresponds to theangle side-to-side. In other embodiments, the angle of the X-axiscorresponds to the incline between one corner and a diagonal corner ofthe landing platform vehicle 100, and the Y-axis corresponds to theincline between a different corner and a diagonal corner of the landingplatform vehicle 100. In some embodiments, the inclinometer may provideangle data as a voltage output such as, for example, from 0 to 5.0Volts. The voltage may be proportional to the angle of that axis. Thevoltage outputs from the inclinometer may be converted into digitalsignals and sent to a controller. In some embodiments, the inclinometermay provide angle data as resistance or current values. In someembodiments, two values may be provided corresponding to each axis.

In some embodiments, each linear actuator 135 may provide a positionfeedback signal. In some embodiments, this signal may be a digitalsignal. In other embodiments, this signal may be an analog signal andmay be converted from analog into digital signal. The position feedbacksignal may be used to determine which linear actuators 135 can beextended and which ones should be retracted to achieve the best levelorientation. For instance, in some situations, raising one corner of thelanding platform vehicle 100 can produce the same effect as lowering theopposite corner of the landing platform vehicle 100. Thus, if one linearactuator 135 may be already near full extension (all the way up), thecontroller can choose to lower that linear actuator 135 rather thanraise a different linear actuator 135 and vice versa.

The landing platform vehicle 100 may include a drive system. In someembodiments, the drive system may include four motors coupled with thefour control arms 130 and the four wheels 125. In some embodiments, thedrive system may be based on four-wheel differential drive architecture.For example, as shown in FIG. 6, each wheel 125 may be driven by its ownmotor 605. The motor 605 may feature a right-angle gearbox that mayallow the motor 605 to be tightly fitted up against the control arm 130.In some embodiments, each motor 605 may be individually controlled,allowing them to move in different directions if necessary. This can bethe basis, for example, for a differential drive system of the landingplatform vehicle 100, in which the wheels 125 on one side of the landingplatform vehicle 100 rotate in the opposite direction from those on theother side of the landing platform vehicle 100. This may cause thelanding platform vehicle 100 to rotate in place, giving it a smallturning radius.

In some embodiments, the drive system may be self-aware. For example,each motor 605 may include a one or two-channel Hall Effect encoder thatcan send pulses to the digital controller. The frequency of thesepulses, for example, may be directly proportional to the speed of themotor 605. The pulses on the two channels may be 90 degrees out of phasewith one another, allowing the controller to also determine thedirection of rotation of each wheel motor 605. The data from the wheel125 encoders may allow the controller to detect if any of the wheels 125are slipping or stalled, that may indicate a problem that may requireshutting down one of the drive motors. Various other techniques may beused to allow the drive system to be self-aware.

In some embodiments the landing surface 102 of the landing platformvehicle 100 may include one, two, three, four, five or more flaps thatmay fold outwardly to create a larger surface. FIG. 7A and 7B illustratea collapsible landing surface 102 with flap 840, flap 841, flap 842,and/or flap 843. FIG. 7A shows these flaps in an open configuration andFIG. 7B shows these flaps in a closed configuration. By opening the flap840, flap 841, flap 842, and/or flap 843 the surface area of the landingsurface 102 may be increased as shown in FIG. 7A.

In some embodiments, folding the landing surface 102 into the closedconfiguration may allow for a more compact and/or more durableconfiguration for transport. In some embodiments, this can beaccomplished by rotating four trapezoidal flaps 180 degrees inward sothat they rest flat on the center section.

In some embodiments, the landing platform vehicle 100 may be compactenough to be carried on the back of a person without impeding movement.In some embodiments the landing surface 102 may have a surface area of2-5 square feet, such as, for example, about three square feet. In someembodiments, the landing platform vehicle 100 may have a height of 5-12inches.

In some embodiments, the landing surface 102 may include eightspring-loaded stainless steel hinges that may force the flaps closed.Two hinges may be coupled with each of the flaps. In some embodiments,the landing surface 102 may use, for example, a motorized cable operatedmechanism to pull the landing surface 102 open. This mechanism may usefour miniature winches to pull each cable over a cam at the edge of thelanding surface 102. For example, the landing surface 102 may be heldopen without the motors requiring any power; only when the motors may bereversed, is the landing surface 102 allowed to close.

FIG. 8 is a block diagram of an electronic system 800 of a landingplatform vehicle 100 according to some embodiments. The electronicsystem 800 may include a controller 805, battery 810, and inclinometer815. The controller 805 may include any type of controller such as, forexample, a controller, a processor, an FGPA, etc. The controller 805 mayexecute algorithms, routines, systems, processes, programs, etc., thatreceive data from the various components of the electronic system 800and/or provide control signals to the various components of theelectronic system 800. The controller 805, for example, may include anycomponent of computational system 1000 shown in FIG. 10. The battery 810may include any number of batteries of various types that can providepower to the controller 805 and/or any other component. In someembodiments, every other component or various components shown in FIG. 8may also be powered by the batteries 810 or other batteries. In someembodiments, the batteries 810 may be electrically coupled with solarcells 811. The solar cells 811, for example, may be coupled with the topsurface of the landing surface 102. The solar cells 811 may collectradiation from the sun that is converted to electricity to charge thebattery 810. Any number and/or type of solar cells may be used. Thesolar cells 811 may include various components that may be used toregulate and/or control the charging of the battery 810.

The inclinometer 815 may include any type of device that can measure anangle relative to gravity in two dimensions. In some embodiments, twoinclinometers may be included—one for each of two orthogonal dimensions.The inclinometer 815 may include, for example, a tilt sensor, anaccelerometer, a 2-axis MEMS inclinometer, etc. In some embodiments, theinclinometer may output one or more values of voltage, current, orresistance, which is proportional to the inclination of the inclinometerrelative to gravity in one or two axis.

In some embodiments, the controller 805 may be electronically coupledwith motor 820, motor 821, motor 822, and/or motor 823 (the motors).Each of the motors may be coupled with a wheel 125 of one of fouractuating wheel assemblies. The controller 805, therefore, may controlthe rotation of each wheel by sending a signal to one of the motors. Insome embodiments, a Pulse Width Modulation (PWM) signal may be sent fromthe controller 805 to one of each of the motors to control the rate ofrotation of the motor.

In some embodiments, the controller 805 may be electronically coupledwith actuator 830, actuator 831, actuator 832, and/or actuator 833 (theactuators). Each of the actuators may be coupled with the body of thelanding platform vehicle 100 and a control arm 130 of an actuating wheelassembly. The controller 805, therefore, may control the angle of eachcontrol arm 130 relative to the landing platform, which may cause thelanding surface 102 to change the ordination of the landing surface 102relative to gravity. In some embodiments, one or more of the actuatorsmay send a feedback signal to the controller 805 that specifies theposition of the actuator and, therefore, the position of the control arm130 relative to the landing surface 102. In some embodiments, a PWMsignal may be sent from the controller 805 to one of each of the motorsto control position of each of the actuators. In some embodiments, eachof the actuators may send position signals back to the controller 805that indicate the linear position of each actuator.

In some embodiments, the controller 805 may be electronically coupledwith flap 840, flap 841, flap 842, and/or flap 843 (the flaps). Anexample configuration of these flaps is shown in FIGS. 7A and 7B. Thecontroller 805 may cause the flaps to open or close creating a largersurface area on the landing surface 102 upon which a UAV 105 may land.In some embodiments, each of the flaps may open or close using anynumber of mechanisms such as, for example, an electronic lock, anelectronic latchet, a electromagnet, a pulley and motor system, a linearactuator, a motor and gear system, etc.

In some embodiments, the landing platform vehicle 100 may provide highamplitude and/or low frequency leveling compensation. For example, acontroller (e.g., controller 805 shown in FIG. 8 and/or the computationsystem 1000 shown in FIG. 10) may coordinate the actuation of the linearactuators 135 in response to inclination data to ensure that the landingsurface 102 is level relative to the horizon. In some embodiments, thelanding platform vehicle 100 may adjust the level of the landing surface102 with three degrees of freedom. In some embodiments, the landingplatform vehicle 100 may adjust the level of the landing surface 102within a ±1%, ±2%, ±3%, ±4%, or ±5% relative to horizontal.

FIG. 9 is a flowchart of an example process 900 for self-leveling,according to at least one embodiment described herein. One or more stepsof the process may be implemented, in some embodiments, by one or morecomponents described herein. Although illustrated as discrete blocks,various blocks may be divided into additional blocks, combined intofewer blocks, or eliminated, depending on the desired implementation. Insome embodiments, the process 900 may be executed by controller 805.

At block 905 inclinometer data is received from the inclinometer 815.The inclinometer data may include data representing the angle of inclineof the landing surface 102 relative to gravity in one or two dimensions.In some embodiments, inclinometer values may be read from theinclinometer 815. In some embodiments, this may include reading one ormore analog voltage values (or current values or resistance values) fromthe inclinometer 815. In some embodiments, this may include convertingan analog voltage value into a digital value.

In some embodiments, control arm position data may also be received fromone or more linear actuators 135.

At block 910 one or more adjustment values may be determined based onthe inclinometer data. In some embodiments, an adjustment value for aspecific linear actuator 135 may depend on the position of one or morecontrol arms 130 relative to the body of the landing platform vehicle100. In some embodiments, the positions of the respective one or morecontrol arms 130 may be determined based on a position signal receivedform the one or more linear actuators 135. In some embodiments, anadjustment value may be determined using a look up table that correlatesan adjustment value with inclinometer data and/or the position of anactuating arm 136 of the linear actuator 135. In some embodiments, theadjustment value for one linear actuator 135 may be determined based theposition of the actuating arms of other linear actuators.

In some embodiments, an adjustment value for a first linear actuator maydepend on the position of an actuating arm of a second linear actuator,a third linear actuator, and/or a fourth linear actuator. For example,the inclination data may indicate that a first linear actuator may beactuated to move a portion of the landing platform surface upwards inorder to level the landing platform surface. The same inclination datamay also indicate that a second linear actuator (and/or a third linearactuator and/or a fourth linear actuator) may be actuated to move aportion of the landing platform downwards in order to level the landingplatform surface. The controller 805 may determine whether to actuatethe first linear actuator or the second linear actuator in order tolevel the landing platform surface. For example, if the first linearactuator position is greater than the position of the second linearactuator and/or if the first linear actuator position is greater than athreshold position value (e.g., the first actuator has been actuatedpast the half way point of actuation) and/or the second linear actuatorposition is less than a threshold position value (e.g., the secondactuator has been actuated past the half way point of actuation) thenthe second linear actuator may be positively actuated to level thelanding platform surface rather than the first linear actuator.Alternatively and/or additionally, as another example, if the firstlinear actuator position is less than the position of the second linearactuator and/or if the first linear actuator position is less than athreshold position value (e.g., the first actuator has been actuatedpast the half way point of actuation) and/or the second linear actuatorposition is greater than a threshold position value (e.g., the secondactuator has been actuated past the half way point of actuation) thenthe first linear actuator may be positively actuated to level thelanding platform surface rather than the first linear actuator.

At block 915 the adjustment value may be sent to one or more linearactuators and the one or more linear actuators may actuate according tothe adjustment value. In some embodiments, the adjustment signal may bea PWM signal where the frequency of pulses and/or the duration of pulsesare proportional to the size of the adjustment value. In someembodiments, the adjustment value may be sent to an actuator control.The actuating controller may send a PWM signal to the actuator.

At block 920 the process 900 may wait a predetermined period of timebefore returning to block 905. In some embodiments, the predeterminedperiod of time may be proportional with the sampling period of theinclinometer. For example, if the inclinometer is sampled at a rate of10 Hz, then the process 900 may wait about one tenth of a second atblock 920.

The computational system 1000 (or processing unit) illustrated in FIG.10 can be used to perform any of the embodiments described within thisdocument. For example, the computational system 1000 can be used aloneor in conjunction with other components. As another example, thecomputational system 1000 can be used to perform any calculation, solveany equation, perform any identification, and/or make any determinationdescribed here. For example, the computational system 1000 may be usedto control the linear actuators and/or the wheel motors. For example,the computational system 1000 may also be used to operate and/or levelthe landing platform vehicle 100.

The computational system 1000 includes hardware elements that can beelectrically coupled via a bus 1005 (or may otherwise be incommunication, as appropriate). The hardware elements can include one ormore processors 1010, including, without limitation, one or moregeneral-purpose processors and/or one or more special-purpose processors(such as digital signal processing chips, graphics acceleration chips,and/or the like); one or more input devices 1015, which can include,without limitation, a mouse, a keyboard, and/or the like; and one ormore output devices 1020, which can include, without limitation, adisplay device, a printer, and/or the like.

The computational system 1000 may further include (and/or be incommunication with) one or more storage devices 1025, which can include,without limitation, local and/or network-accessible storage and/or caninclude, without limitation, a disk drive, a drive array, an opticalstorage device, a solid-state storage device, such as random accessmemory (“RAM”) and/or read-only memory (“ROM”), which can beprogrammable, flash-updateable, and/or the like. The computationalsystem 1000 might also include a communications subsystem 1030, whichcan include, without limitation, a modem, a network card (wireless orwired), an infrared communication device, a wireless communicationdevice, and/or chipset (such as a Bluetooth® device, a 802.6 device, aWiFi device, a WiMAX device, cellular communication facilities, etc.),and/or the like. The communications subsystem 1030 may permit data to beexchanged with a network (such as the network described below, to nameone example) and/or any other devices described herein. In manyembodiments, the computational system 1000 will further include aworking memory 1035, which can include a RAM or ROM device, as describedabove.

The computational system 1000 also can include software elements, shownas being currently located within the working memory 1035, including anoperating system 1040 and/or other code, such as one or more applicationprograms 1045, which may include computer programs of the invention,and/or may be designed to implement methods of the invention and/orconfigure systems of the invention, as described herein. For example,one or more procedures described with respect to the method(s) discussedabove might be implemented as code and/or instructions executable by acomputer (and/or a processor within a computer). A set of theseinstructions and/or codes might be stored on a computer-readable storagemedium, such as the storage device(s) 1025 described above. In somecases, the storage medium might be incorporated within the computationalsystem 1000 or in communication with the computational system 1000. Inother embodiments, the storage medium might be separate from thecomputational system 1000 (e.g., a removable medium, such as a compactdisc, etc.), and/or provided in an installation package, such that thestorage medium can be used to program a general-purpose computer withthe instructions/code stored thereon. These instructions might take theform of executable code, which may be executable by the computationalsystem 1000 and/or might take the form of source and/or installablecode, which, upon compilation and/or installation on the computationalsystem 1000 (e.g., using any of a variety of generally availablecompilers, installation programs, compression/decompression utilities,etc.), then takes the form of executable code.

The term “substantially” means within 5% or 10% of the value referred toor within manufacturing tolerances.

Numerous specific details are set forth herein to provide a thoroughunderstanding of the claimed subject matter. However, those skilled inthe art will understand that the claimed subject matter may be practicedwithout these specific details. In other instances, methods,apparatuses, or systems that would be known by one of ordinary skillhave not been described in detail so as not to obscure claimed subjectmatter.

Some portions are presented in terms of algorithms or symbolicrepresentations of operations on data bits or binary digital signalsstored within a computing system memory, such as a computer memory.These algorithmic descriptions or representations are examples oftechniques used by those of ordinary skill in the data processing art toconvey the substance of their work to others skilled in the art. Analgorithm may be a self-consistent sequence of operations or similarprocessing leading to a desired result. In this context, operations orprocessing involves physical manipulation of physical quantities.Typically, although not necessarily, such quantities may take the formof electrical or magnetic signals capable of being stored, transferred,combined, compared, or otherwise manipulated. It has proven convenientat times, principally for reasons of common usage, to refer to suchsignals as bits, data, values, elements, symbols, characters, terms,numbers, numerals, or the like. It should be understood, however, thatall of these and similar terms are to be associated with appropriatephysical quantities and are merely convenient labels. Unlessspecifically stated otherwise, it is appreciated that throughout thisspecification discussions utilizing terms such as “processing,”“computing,” “calculating,” “determining,” and “identifying” or the likerefer to actions or processes of a computing device, such as one or morecomputers or a similar electronic computing device or devices, thatmanipulate or transform data represented as physical, electronic, ormagnetic quantities within memories, registers, or other informationstorage devices, transmission devices, or display devices of thecomputing platform.

The system or systems discussed herein are not limited to any particularhardware architecture or configuration. A computing device can includeany suitable arrangement of components that provides a resultconditioned on one or more inputs. Suitable computing devices includemultipurpose microprocessor-based computer systems accessing storedsoftware that programs or configures the computing system from ageneral-purpose computing apparatus to a specialized computing apparatusimplementing one or more embodiments of the present subject matter. Anysuitable programming, scripting, or other type of language orcombinations of languages may be used to implement the teachingscontained herein in software to be used in programming or configuring acomputing device.

Embodiments of the methods disclosed herein may be performed in theoperation of such computing devices. The order of the blocks presentedin the examples above can be varied—for example, blocks can bere-ordered, combined, and/or broken into sub-blocks. Certain blocks orprocesses can be performed in parallel.

The use of “adapted to” or “configured to” herein is meant as open andinclusive language that does not foreclose devices adapted to orconfigured to perform additional tasks or steps. Additionally, the useof “based on” is meant to be open and inclusive, in that a process,step, calculation, or other action “based on” one or more recitedconditions or values may, in practice, be based on additional conditionsor values beyond those recited. Headings, lists, and numbering includedherein are for ease of explanation only and are not meant to belimiting.

While the present subject matter has been described in detail withrespect to specific embodiments thereof, it will be appreciated thatthose skilled in the art, upon attaining an understanding of theforegoing, may readily produce alterations to, variations of, andequivalents to such embodiments. Accordingly, it should be understoodthat the present disclosure has been presented for-purposes of examplerather than limitation, and does not preclude inclusion of suchmodifications, variations, and/or additions to the present subjectmatter as would be readily apparent to one of ordinary skill in the art.

That which is claimed:
 1. A mobile landing platform vehicle comprising:a landing platform body; a landing platform surface; an inclinometer; afirst actuating wheel assembly including a first wheel, a first controlarm coupled with the first wheel, and a first linear actuator coupledwith the landing platform body and the first control arm; a secondactuating wheel assembly including a second wheel, a second control armcoupled with the second wheel, and a second linear actuator coupled withthe landing platform body and the second control arm; a third actuatingwheel assembly including a third wheel, a third control arm coupled withthe third wheel, and a third linear actuator coupled with the landingplatform body and the third control arm; a fourth actuating wheelassembly including a fourth wheel, a fourth control arm coupled with thefourth wheel, and a fourth linear actuator coupled with the landingplatform body and the fourth control arm; and a controllercommunicatively coupled with the inclinometer, the first actuator, thesecond actuator, the third actuator, and the fourth actuator, thecontroller configured to determine and send at least one adjustmentvalue to the first actuator, the second actuator, the third actuator,and the fourth actuator to maintain a level landing platform surface. 2.The mobile landing platform vehicle as claimed in claim 1, wherein theat least one adjustment value is determined from data received from theinclinometer.
 3. The mobile landing platform vehicle as claimed in claim1, wherein the inclinometer comprises a dual axis inclinometer.
 4. Themobile landing platform vehicle as claimed in claim 1, furthercomprising a first linear actuator controller communicatively coupledwith the controller and the first linear actuator, a second linearactuator controller communicatively coupled with the controller and thesecond linear actuator, a third linear actuator controllercommunicatively coupled with the controller and the third linearactuator, and a fourth linear actuator controller communicativelycoupled with the controller and the fourth linear actuator.
 5. Themobile landing platform vehicle as claimed in claim 1, wherein thecontroller is configured to receive position data from the first linearactuator, the second linear actuator, the third linear actuator, and thefourth linear actuator, wherein the at least one adjustment value isdetermined based on the position data.
 6. A mobile landing platformvehicle comprising: a landing platform body having a landing platformsurface; four actuating wheel assemblies coupled with the landingplatform body, each actuating wheel assembly comprising: a wheel; acontrol arm coupled with the wheel and the landing platform body; and anactuator coupled with the control arm and the landing platform body; aninclinometer; and a controller coupled with the inclinometer and eachactuator of the four actuating wheel assemblies, wherein the controlleris configured to keep the landing platform surface level based oninclination data received from the inclinometer and by sending controlsignals to the actuators of the four actuating wheel assemblies.
 7. Themobile landing platform vehicle as claimed in claim 6, wherein eachactuating wheel assembly further comprises a wheel motor coupled withthe control arm and the wheel, each wheel motor configured to rotate awheel of each actuating wheel assembly.
 8. The mobile landing platformvehicle as claimed in claim 6, wherein the inclinometer comprises a dualaxis inclinometer.
 9. The mobile landing platform vehicle as claimed inclaim 6, wherein each of the four actuating wheel assemblies comprise alinear actuator controller in communication with the controller.
 10. Themobile landing platform vehicle as claimed in claim 6, wherein each ofthe four actuating wheel assemblies may send position feedback signalsthat indicate the position of the respective actuating wheel assembly.11. The mobile landing platform vehicle as claimed in claim 6, furthercomprising: one or more batteries; and one or more solar cells disposedon the landing platform surface electrically coupled with the one ormore batteries.
 12. The mobile landing platform vehicle as claimed inclaim 11, wherein the controller is configured to tilt the landingplatform surface at an angle relative to horizontal that produces anincreased power from the one or more solar cells.
 13. The mobile landingplatform vehicle as claimed in claim 6, wherein the landing platformfurther comprises a plurality of flaps that extend from the landingplatform surface to increase the surface area of the landing platformsurface.
 14. A method for leveling a mobile landing platform vehicle,the method comprising: receiving inclinometer data from an inclinometercoupled with the mobile landing platform; receiving actuator positiondata from at least one of a first linear actuator, a second linearactuator, a third linear actuator, and a fourth linear actuator;determining an adjustment value for the first linear actuator based onthe inclinometer data and the actuator position data; and sending theadjustment value to the first linear actuator.
 15. The method accordingto claim 14, wherein the mobile landing platform includes: a firstactuating wheel assembly comprising the first linear actuator, a firstwheel, and a first control arm coupled with the first linear actuatorand the first wheel; a third actuating wheel assembly comprising thethird linear actuator, a third wheel, and a third control arm coupledwith the third linear actuator and the third wheel; and a fourthactuating wheel assembly comprising the fourth linear actuator, a fourthwheel, and a fourth control arm coupled with the fourth linear actuatorand the fourth wheel.
 16. The method according to claim 14, wherein theadjustment value comprises a pulse width modulation signal.
 17. Themethod according to claim 14, wherein determining an adjustment valuefor the first linear actuator based on the inclinometer data and theactuator position data, further comprises determining an adjustmentvalue for the first linear actuator based on the inclinometer data andthe actuator position data of the first linear actuator and actuatorposition data of at least one of the second linear actuator, the thirdlinear actuator, and the fourth linear actuator.
 18. The methodaccording to claim 14, further comprising determining whether one ormore of the first linear actuator, a second linear actuator, a thirdlinear actuator, and a fourth linear actuator is extended beyond athreshold value.